81358177 has 4 divisors (see below), whose sum is σ = 82338480. Its totient is φ = 80377876.

The previous prime is 81358159. The next prime is 81358181. The reversal of 81358177 is 77185318.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81358177 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81358117) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 490027 + ... + 490192.

It is an arithmetic number, because the mean of its divisors is an integer number (20584620).

Almost surely, 2^81358177 is an apocalyptic number.

It is an amenable number.

81358177 is a deficient number, since it is larger than the sum of its proper divisors (980303).

81358177 is an equidigital number, since it uses as much as digits as its factorization.

81358177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980302.

The product of its digits is 47040, while the sum is 40.

The square root of 81358177 is about 9019.8767729942. The cubic root of 81358177 is about 433.3116872159.

The spelling of 81358177 in words is "eighty-one million, three hundred fifty-eight thousand, one hundred seventy-seven".